The field of the invention is compositions for mercerizing cellulose fibers.
The mercerizing of cellulose fibers is a well-known operation during textile finishing.
The mercerizing step imparts to the cellulose fibers increased luster, improved dyeability, higher tear strength, better moisture absorption, and higher lightfastness and weathering resistance.
The mercerizing process resides in treating the cellulose containing fiber material, which is under tension, with alkali solutions of a high concentration at predominantly low temperatures.
In order to have the mercerizing procedure take place rapidly, thus ensuring a high throughput and a satisfactory economy of the processes, the fiber must be soaked quickly and uniformly with the alkali solution.
Since high-percentage alkali hydroxide solutions exhibit a high surface tension, the use of wetting agents is ncessary. It has been known to add phenols and phenol derivatives to the mercerizing solution (see Lindner, "Tenside-Textilhilfsmittel-Waschrohstoffe" [Tensides--Auxiliary Textile Agents--Detergent Raw Materials] [1964] vol. II, pp. 1,476-1,478). The phenolates formed in the alkali solution actually are not as yet wetting agents, but they act as hydrotropic compounds and emulsifiers on the actual active agents causing the wetting effect. Such active agents are, for example, alkanesulfonates and alkyl sulfates.
Compositions containing phenol and phenol derivatives have only little significance nowadays due to the large amounts which must be employed (10-20 g./l.) and due to the troublesome odor, and they are no longer used, above all, because the phenols are considerably toxic to fish.
However, phenol-free mercerizing agents are likewise known. These are primarily alkanesulfonates and alkyl sulfates as disclosed in German Published Application No. 1,154,460, as well as mixtures thereof, as they are available in several known commercial products. These prior-art agents impart a certain wettability to the highly concentrated solutions of alkali, but this wettability is not as yet fully satisfactory. Furthermore, the solubility of the agents of the prior art in highly concentrated alkali solutions is not always adequate.